This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | -3 |
| 3 | -3 |
| 4 | 217 |
| 5 | -2951 |
| 6 | 5973 |
| 7 | 1237173 |
| 8 | -52635599 |
| 9 | 1126610929 |
| 10 | 20058390573 |
| 11 | -3920482183827 |
| 12 | 256734635981833 |
| 13 | -8529964147714967 |
| 14 | -383670903748980603 |
| 15 | 99786978811973617701 |
| 16 | -10380441423510120242591 |
| 17 | 594094494902602207843297 |